The effect of a national control program on mastitis occurrence in the Netherlands

Abstract

A 5-year national mastitis control program was initiated in the Netherlands in 2005. Knowledge transfer and improvements of dairy farmers’ motivation towards udder health were used as means to decrease mastitis occurrence in Dutch dairy herds. The aim of this study was to determine the effect of the control program on (sub)clinical mastitis occurrence and on farmers’ mindset and behaviour in relation to clinical mastitis. Two identical surveys were conducted in the same herds at the beginning and end of the control program to quantify the change in mastitis occurrence and farmers’ mindset and behaviour. Prevalence of high composite somatic cell count (CSCC) and incidence rate of farmer-diagnosed clinical mastitis (IRCM) were compared between both surveys. The change in farmers’ mindset and behaviour towards udder health was associated with the change in IRCM in 104 dairy herds using factor analyses and linear regression models. There was no significant decrease in high CSCC prevalence between both surveys. However, IRCM decreased from 33.5 in 2004/2005 to 28.1 quarter cases per 100 cow-years at risk in 2009. The variation in the change in IRCM was mainly explained by the 2004/2005 IRCM (29%) and factors describing the change in farmers’ mindset (20%). These factors described a change in the perceived lack of control, a change in the perceived lack of influence on sources of mastitis, and a change in the worries about mastitis. This study indicated that udder health was improved in the Netherlands over the course of a mastitis control program. Changing dairy farmers’ mindset seemed effective in decreasing clinical mastitis occurrence in dairy herds.Keywordsudder health programmastitisprevalenceincidence ratemindset